arch/powerpc/kernel/irq.c

   1 /*
   2  *  Derived from arch/i386/kernel/irq.c
   3  *    Copyright (C) 1992 Linus Torvalds
   4  *  Adapted from arch/i386 by Gary Thomas
   5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   6  *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
   7  *    Copyright (C) 1996-2001 Cort Dougan
   8  *  Adapted for Power Macintosh by Paul Mackerras
   9  *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version
  14  * 2 of the License, or (at your option) any later version.
  15  *
  16  * This file contains the code used by various IRQ handling routines:
  17  * asking for different IRQ's should be done through these routines
  18  * instead of just grabbing them. Thus setups with different IRQ numbers
  19  * shouldn't result in any weird surprises, and installing new handlers
  20  * should be easier.
  21  *
  22  * The MPC8xx has an interrupt mask in the SIU.  If a bit is set, the
  23  * interrupt is _enabled_.  As expected, IRQ0 is bit 0 in the 32-bit
  24  * mask register (of which only 16 are defined), hence the weird shifting
  25  * and complement of the cached_irq_mask.  I want to be able to stuff
  26  * this right into the SIU SMASK register.
  27  * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
  28  * to reduce code space and undefined function references.
  29  */
  30
  31 #undef DEBUG
  32
  33 #include <linux/export.h>
  34 #include <linux/threads.h>
  35 #include <linux/kernel_stat.h>
  36 #include <linux/signal.h>
  37 #include <linux/sched.h>
  38 #include <linux/ptrace.h>
  39 #include <linux/ioport.h>
  40 #include <linux/interrupt.h>
  41 #include <linux/timex.h>
  42 #include <linux/init.h>
  43 #include <linux/slab.h>
  44 #include <linux/delay.h>
  45 #include <linux/irq.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/cpumask.h>
  48 #include <linux/profile.h>
  49 #include <linux/bitops.h>
  50 #include <linux/list.h>
  51 #include <linux/radix-tree.h>
  52 #include <linux/mutex.h>
  53 #include <linux/bootmem.h>
  54 #include <linux/pci.h>
  55 #include <linux/debugfs.h>
  56 #include <linux/of.h>
  57 #include <linux/of_irq.h>
  58
  59 #include <asm/uaccess.h>
  60 #include <asm/system.h>
  61 #include <asm/io.h>
  62 #include <asm/pgtable.h>
  63 #include <asm/irq.h>
  64 #include <asm/cache.h>
  65 #include <asm/prom.h>
  66 #include <asm/ptrace.h>
  67 #include <asm/machdep.h>
  68 #include <asm/udbg.h>
  69 #include <asm/smp.h>
  70
  71 #ifdef CONFIG_PPC64
  72 #include <asm/paca.h>
  73 #include <asm/firmware.h>
  74 #include <asm/lv1call.h>
  75 #endif
  76 #define CREATE_TRACE_POINTS
  77 #include <asm/trace.h>
  78
  79 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
  80 EXPORT_PER_CPU_SYMBOL(irq_stat);
  81
  82 int __irq_offset_value;
  83
  84 #ifdef CONFIG_PPC32
  85 EXPORT_SYMBOL(__irq_offset_value);
  86 atomic_t ppc_n_lost_interrupts;
  87
  88 #ifdef CONFIG_TAU_INT
  89 extern int tau_initialized;
  90 extern int tau_interrupts(int);
  91 #endif
  92 #endif /* CONFIG_PPC32 */
  93
  94 #ifdef CONFIG_PPC64
  95
  96 #ifndef CONFIG_SPARSE_IRQ
  97 EXPORT_SYMBOL(irq_desc);
  98 #endif
  99
 100 int distribute_irqs = 1;
 101
 102 static inline notrace unsigned long get_hard_enabled(void)
 103 {
 104         unsigned long enabled;
 105
 106         __asm__ __volatile__("lbz %0,%1(13)"
 107         : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
 108
 109         return enabled;
 110 }
 111
 112 static inline notrace void set_soft_enabled(unsigned long enable)
 113 {
 114         __asm__ __volatile__("stb %0,%1(13)"
 115         : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
 116 }
 117
 118 notrace void arch_local_irq_restore(unsigned long en)
 119 {
 120         /*
 121          * get_paca()->soft_enabled = en;
 122          * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
 123          * That was allowed before, and in such a case we do need to take care
 124          * that gcc will set soft_enabled directly via r13, not choose to use
 125          * an intermediate register, lest we're preempted to a different cpu.
 126          */
 127         set_soft_enabled(en);
 128         if (!en)
 129                 return;
 130
 131 #ifdef CONFIG_PPC_STD_MMU_64
 132         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
 133                 /*
 134                  * Do we need to disable preemption here?  Not really: in the
 135                  * unlikely event that we're preempted to a different cpu in
 136                  * between getting r13, loading its lppaca_ptr, and loading
 137                  * its any_int, we might call iseries_handle_interrupts without
 138                  * an interrupt pending on the new cpu, but that's no disaster,
 139                  * is it?  And the business of preempting us off the old cpu
 140                  * would itself involve a local_irq_restore which handles the
 141                  * interrupt to that cpu.
 142                  *
 143                  * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
 144                  * to avoid any preemption checking added into get_paca().
 145                  */
 146                 if (local_paca->lppaca_ptr->int_dword.any_int)
 147                         iseries_handle_interrupts();
 148         }
 149 #endif /* CONFIG_PPC_STD_MMU_64 */
 150
 151         /*
 152          * if (get_paca()->hard_enabled) return;
 153          * But again we need to take care that gcc gets hard_enabled directly
 154          * via r13, not choose to use an intermediate register, lest we're
 155          * preempted to a different cpu in between the two instructions.
 156          */
 157         if (get_hard_enabled())
 158                 return;
 159
 160         /*
 161          * Need to hard-enable interrupts here.  Since currently disabled,
 162          * no need to take further asm precautions against preemption; but
 163          * use local_paca instead of get_paca() to avoid preemption checking.
 164          */
 165         local_paca->hard_enabled = en;
 166
 167         /*
 168          * Trigger the decrementer if we have a pending event. Some processors
 169          * only trigger on edge transitions of the sign bit. We might also
 170          * have disabled interrupts long enough that the decrementer wrapped
 171          * to positive.
 172          */
 173         decrementer_check_overflow();
 174
 175         /*
 176          * Force the delivery of pending soft-disabled interrupts on PS3.
 177          * Any HV call will have this side effect.
 178          */
 179         if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
 180                 u64 tmp;
 181                 lv1_get_version_info(&tmp);
 182         }
 183
 184         __hard_irq_enable();
 185 }
 186 EXPORT_SYMBOL(arch_local_irq_restore);
 187 #endif /* CONFIG_PPC64 */
 188
 189 int arch_show_interrupts(struct seq_file *p, int prec)
 190 {
 191         int j;
 192
 193 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
 194         if (tau_initialized) {
 195                 seq_printf(p, "%*s: ", prec, "TAU");
 196                 for_each_online_cpu(j)
 197                         seq_printf(p, "%10u ", tau_interrupts(j));
 198                 seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 199         }
 200 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT */
 201
 202         seq_printf(p, "%*s: ", prec, "LOC");
 203         for_each_online_cpu(j)
 204                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs);
 205         seq_printf(p, "  Local timer interrupts\n");
 206
 207         seq_printf(p, "%*s: ", prec, "SPU");
 208         for_each_online_cpu(j)
 209                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs);
 210         seq_printf(p, "  Spurious interrupts\n");
 211
 212         seq_printf(p, "%*s: ", prec, "CNT");
 213         for_each_online_cpu(j)
 214                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);
 215         seq_printf(p, "  Performance monitoring interrupts\n");
 216
 217         seq_printf(p, "%*s: ", prec, "MCE");
 218         for_each_online_cpu(j)
 219                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
 220         seq_printf(p, "  Machine check exceptions\n");
 221
 222         return 0;
 223 }
 224
 225 /*
 226  * /proc/stat helpers
 227  */
 228 u64 arch_irq_stat_cpu(unsigned int cpu)
 229 {
 230         u64 sum = per_cpu(irq_stat, cpu).timer_irqs;
 231
 232         sum += per_cpu(irq_stat, cpu).pmu_irqs;
 233         sum += per_cpu(irq_stat, cpu).mce_exceptions;
 234         sum += per_cpu(irq_stat, cpu).spurious_irqs;
 235
 236         return sum;
 237 }
 238
 239 #ifdef CONFIG_HOTPLUG_CPU
 240 void migrate_irqs(void)
 241 {
 242         struct irq_desc *desc;
 243         unsigned int irq;
 244         static int warned;
 245         cpumask_var_t mask;
 246         const struct cpumask *map = cpu_online_mask;
 247
 248         alloc_cpumask_var(&mask, GFP_KERNEL);
 249
 250         for_each_irq(irq) {
 251                 struct irq_data *data;
 252                 struct irq_chip *chip;
 253
 254                 desc = irq_to_desc(irq);
 255                 if (!desc)
 256                         continue;
 257
 258                 data = irq_desc_get_irq_data(desc);
 259                 if (irqd_is_per_cpu(data))
 260                         continue;
 261
 262                 chip = irq_data_get_irq_chip(data);
 263
 264                 cpumask_and(mask, data->affinity, map);
 265                 if (cpumask_any(mask) >= nr_cpu_ids) {
 266                         printk("Breaking affinity for irq %i\n", irq);
 267                         cpumask_copy(mask, map);
 268                 }
 269                 if (chip->irq_set_affinity)
 270                         chip->irq_set_affinity(data, mask, true);
 271                 else if (desc->action && !(warned++))
 272                         printk("Cannot set affinity for irq %i\n", irq);
 273         }
 274
 275         free_cpumask_var(mask);
 276
 277         local_irq_enable();
 278         mdelay(1);
 279         local_irq_disable();
 280 }
 281 #endif
 282
 283 static inline void handle_one_irq(unsigned int irq)
 284 {
 285         struct thread_info *curtp, *irqtp;
 286         unsigned long saved_sp_limit;
 287         struct irq_desc *desc;
 288
 289         desc = irq_to_desc(irq);
 290         if (!desc)
 291                 return;
 292
 293         /* Switch to the irq stack to handle this */
 294         curtp = current_thread_info();
 295         irqtp = hardirq_ctx[smp_processor_id()];
 296
 297         if (curtp == irqtp) {
 298                 /* We're already on the irq stack, just handle it */
 299                 desc->handle_irq(irq, desc);
 300                 return;
 301         }
 302
 303         saved_sp_limit = current->thread.ksp_limit;
 304
 305         irqtp->task = curtp->task;
 306         irqtp->flags = 0;
 307
 308         /* Copy the softirq bits in preempt_count so that the
 309          * softirq checks work in the hardirq context. */
 310         irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) |
 311                                (curtp->preempt_count & SOFTIRQ_MASK);
 312
 313         current->thread.ksp_limit = (unsigned long)irqtp +
 314                 _ALIGN_UP(sizeof(struct thread_info), 16);
 315
 316         call_handle_irq(irq, desc, irqtp, desc->handle_irq);
 317         current->thread.ksp_limit = saved_sp_limit;
 318         irqtp->task = NULL;
 319
 320         /* Set any flag that may have been set on the
 321          * alternate stack
 322          */
 323         if (irqtp->flags)
 324                 set_bits(irqtp->flags, &curtp->flags);
 325 }
 326
 327 static inline void check_stack_overflow(void)
 328 {
 329 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 330         long sp;
 331
 332         sp = __get_SP() & (THREAD_SIZE-1);
 333
 334         /* check for stack overflow: is there less than 2KB free? */
 335         if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 336                 printk("do_IRQ: stack overflow: %ld\n",
 337                         sp - sizeof(struct thread_info));
 338                 dump_stack();
 339         }
 340 #endif
 341 }
 342
 343 void do_IRQ(struct pt_regs *regs)
 344 {
 345         struct pt_regs *old_regs = set_irq_regs(regs);
 346         unsigned int irq;
 347
 348         trace_irq_entry(regs);
 349
 350         irq_enter();
 351
 352         check_stack_overflow();
 353
 354         irq = ppc_md.get_irq();
 355
 356         if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
 357                 handle_one_irq(irq);
 358         else if (irq != NO_IRQ_IGNORE)
 359                 __get_cpu_var(irq_stat).spurious_irqs++;
 360
 361         irq_exit();
 362         set_irq_regs(old_regs);
 363
 364 #ifdef CONFIG_PPC_ISERIES
 365         if (firmware_has_feature(FW_FEATURE_ISERIES) &&
 366                         get_lppaca()->int_dword.fields.decr_int) {
 367                 get_lppaca()->int_dword.fields.decr_int = 0;
 368                 /* Signal a fake decrementer interrupt */
 369                 timer_interrupt(regs);
 370         }
 371 #endif
 372
 373         trace_irq_exit(regs);
 374 }
 375
 376 void __init init_IRQ(void)
 377 {
 378         if (ppc_md.init_IRQ)
 379                 ppc_md.init_IRQ();
 380
 381         exc_lvl_ctx_init();
 382
 383         irq_ctx_init();
 384 }
 385
 386 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 387 struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
 388 struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
 389 struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 390
 391 void exc_lvl_ctx_init(void)
 392 {
 393         struct thread_info *tp;
 394         int i, cpu_nr;
 395
 396         for_each_possible_cpu(i) {
 397 #ifdef CONFIG_PPC64
 398                 cpu_nr = i;
 399 #else
 400                 cpu_nr = get_hard_smp_processor_id(i);
 401 #endif
 402                 memset((void *)critirq_ctx[cpu_nr], 0, THREAD_SIZE);
 403                 tp = critirq_ctx[cpu_nr];
 404                 tp->cpu = cpu_nr;
 405                 tp->preempt_count = 0;
 406
 407 #ifdef CONFIG_BOOKE
 408                 memset((void *)dbgirq_ctx[cpu_nr], 0, THREAD_SIZE);
 409                 tp = dbgirq_ctx[cpu_nr];
 410                 tp->cpu = cpu_nr;
 411                 tp->preempt_count = 0;
 412
 413                 memset((void *)mcheckirq_ctx[cpu_nr], 0, THREAD_SIZE);
 414                 tp = mcheckirq_ctx[cpu_nr];
 415                 tp->cpu = cpu_nr;
 416                 tp->preempt_count = HARDIRQ_OFFSET;
 417 #endif
 418         }
 419 }
 420 #endif
 421
 422 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 423 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 424
 425 void irq_ctx_init(void)
 426 {
 427         struct thread_info *tp;
 428         int i;
 429
 430         for_each_possible_cpu(i) {
 431                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 432                 tp = softirq_ctx[i];
 433                 tp->cpu = i;
 434                 tp->preempt_count = 0;
 435
 436                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 437                 tp = hardirq_ctx[i];
 438                 tp->cpu = i;
 439                 tp->preempt_count = HARDIRQ_OFFSET;
 440         }
 441 }
 442
 443 static inline void do_softirq_onstack(void)
 444 {
 445         struct thread_info *curtp, *irqtp;
 446         unsigned long saved_sp_limit = current->thread.ksp_limit;
 447
 448         curtp = current_thread_info();
 449         irqtp = softirq_ctx[smp_processor_id()];
 450         irqtp->task = curtp->task;
 451         irqtp->flags = 0;
 452         current->thread.ksp_limit = (unsigned long)irqtp +
 453                                     _ALIGN_UP(sizeof(struct thread_info), 16);
 454         call_do_softirq(irqtp);
 455         current->thread.ksp_limit = saved_sp_limit;
 456         irqtp->task = NULL;
 457
 458         /* Set any flag that may have been set on the
 459          * alternate stack
 460          */
 461         if (irqtp->flags)
 462                 set_bits(irqtp->flags, &curtp->flags);
 463 }
 464
 465 void do_softirq(void)
 466 {
 467         unsigned long flags;
 468
 469         if (in_interrupt())
 470                 return;
 471
 472         local_irq_save(flags);
 473
 474         if (local_softirq_pending())
 475                 do_softirq_onstack();
 476
 477         local_irq_restore(flags);
 478 }
 479
 480
 481 /*
 482  * IRQ controller and virtual interrupts
 483  */
 484
 485 /* The main irq map itself is an array of NR_IRQ entries containing the
 486  * associate host and irq number. An entry with a host of NULL is free.
 487  * An entry can be allocated if it's free, the allocator always then sets
 488  * hwirq first to the host's invalid irq number and then fills ops.
 489  */
 490 struct irq_map_entry {
 491         irq_hw_number_t hwirq;
 492         struct irq_host *host;
 493 };
 494
 495 static LIST_HEAD(irq_hosts);
 496 static DEFINE_RAW_SPINLOCK(irq_big_lock);
 497 static DEFINE_MUTEX(revmap_trees_mutex);
 498 static struct irq_map_entry irq_map[NR_IRQS];
 499 static unsigned int irq_virq_count = NR_IRQS;
 500 static struct irq_host *irq_default_host;
 501
 502 irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
 503 {
 504         return irq_map[d->irq].hwirq;
 505 }
 506 EXPORT_SYMBOL_GPL(irqd_to_hwirq);
 507
 508 irq_hw_number_t virq_to_hw(unsigned int virq)
 509 {
 510         return irq_map[virq].hwirq;
 511 }
 512 EXPORT_SYMBOL_GPL(virq_to_hw);
 513
 514 bool virq_is_host(unsigned int virq, struct irq_host *host)
 515 {
 516         return irq_map[virq].host == host;
 517 }
 518 EXPORT_SYMBOL_GPL(virq_is_host);
 519
 520 static int default_irq_host_match(struct irq_host *h, struct device_node *np)
 521 {
 522         return h->of_node != NULL && h->of_node == np;
 523 }
 524
 525 struct irq_host *irq_alloc_host(struct device_node *of_node,
 526                                 unsigned int revmap_type,
 527                                 unsigned int revmap_arg,
 528                                 struct irq_host_ops *ops,
 529                                 irq_hw_number_t inval_irq)
 530 {
 531         struct irq_host *host;
 532         unsigned int size = sizeof(struct irq_host);
 533         unsigned int i;
 534         unsigned int *rmap;
 535         unsigned long flags;
 536
 537         /* Allocate structure and revmap table if using linear mapping */
 538         if (revmap_type == IRQ_HOST_MAP_LINEAR)
 539                 size += revmap_arg * sizeof(unsigned int);
 540         host = kzalloc(size, GFP_KERNEL);
 541         if (host == NULL)
 542                 return NULL;
 543
 544         /* Fill structure */
 545         host->revmap_type = revmap_type;
 546         host->inval_irq = inval_irq;
 547         host->ops = ops;
 548         host->of_node = of_node_get(of_node);
 549
 550         if (host->ops->match == NULL)
 551                 host->ops->match = default_irq_host_match;
 552
 553         raw_spin_lock_irqsave(&irq_big_lock, flags);
 554
 555         /* If it's a legacy controller, check for duplicates and
 556          * mark it as allocated (we use irq 0 host pointer for that
 557          */
 558         if (revmap_type == IRQ_HOST_MAP_LEGACY) {
 559                 if (irq_map[0].host != NULL) {
 560                         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 561                         of_node_put(host->of_node);
 562                         kfree(host);
 563                         return NULL;
 564                 }
 565                 irq_map[0].host = host;
 566         }
 567
 568         list_add(&host->link, &irq_hosts);
 569         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 570
 571         /* Additional setups per revmap type */
 572         switch(revmap_type) {
 573         case IRQ_HOST_MAP_LEGACY:
 574                 /* 0 is always the invalid number for legacy */
 575                 host->inval_irq = 0;
 576                 /* setup us as the host for all legacy interrupts */
 577                 for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
 578                         irq_map[i].hwirq = i;
 579                         smp_wmb();
 580                         irq_map[i].host = host;
 581                         smp_wmb();
 582
 583                         /* Legacy flags are left to default at this point,
 584                          * one can then use irq_create_mapping() to
 585                          * explicitly change them
 586                          */
 587                         ops->map(host, i, i);
 588
 589                         /* Clear norequest flags */
 590                         irq_clear_status_flags(i, IRQ_NOREQUEST);
 591                 }
 592                 break;
 593         case IRQ_HOST_MAP_LINEAR:
 594                 rmap = (unsigned int *)(host + 1);
 595                 for (i = 0; i < revmap_arg; i++)
 596                         rmap[i] = NO_IRQ;
 597                 host->revmap_data.linear.size = revmap_arg;
 598                 smp_wmb();
 599                 host->revmap_data.linear.revmap = rmap;
 600                 break;
 601         case IRQ_HOST_MAP_TREE:
 602                 INIT_RADIX_TREE(&host->revmap_data.tree, GFP_KERNEL);
 603                 break;
 604         default:
 605                 break;
 606         }
 607
 608         pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
 609
 610         return host;
 611 }
 612
 613 struct irq_host *irq_find_host(struct device_node *node)
 614 {
 615         struct irq_host *h, *found = NULL;
 616         unsigned long flags;
 617
 618         /* We might want to match the legacy controller last since
 619          * it might potentially be set to match all interrupts in
 620          * the absence of a device node. This isn't a problem so far
 621          * yet though...
 622          */
 623         raw_spin_lock_irqsave(&irq_big_lock, flags);
 624         list_for_each_entry(h, &irq_hosts, link)
 625                 if (h->ops->match(h, node)) {
 626                         found = h;
 627                         break;
 628                 }
 629         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
 630         return found;
 631 }
 632 EXPORT_SYMBOL_GPL(irq_find_host);
 633
 634 void irq_set_default_host(struct irq_host *host)
 635 {
 636         pr_debug("irq: Default host set to @0x%p\n", host);
 637
 638         irq_default_host = host;
 639 }
 640
 641 void irq_set_virq_count(unsigned int count)
 642 {
 643         pr_debug("irq: Trying to set virq count to %d\n", count);
 644
 645         BUG_ON(count < NUM_ISA_INTERRUPTS);
 646         if (count < NR_IRQS)
 647                 irq_virq_count = count;
 648 }
 649
 650 static int irq_setup_virq(struct irq_host *host, unsigned int virq,
 651                             irq_hw_number_t hwirq)
 652 {
 653         int res;
 654
 655         res = irq_alloc_desc_at(virq, 0);
 656         if (res != virq) {
 657                 pr_debug("irq: -> allocating desc failed\n");
 658                 goto error;
 659         }
 660
 661         /* map it */
 662         smp_wmb();
 663         irq_map[virq].hwirq = hwirq;
 664         smp_mb();
 665
 666         if (host->ops->map(host, virq, hwirq)) {
 667                 pr_debug("irq: -> mapping failed, freeing\n");
 668                 goto errdesc;
 669         }
 670
 671         irq_clear_status_flags(virq, IRQ_NOREQUEST);
 672
 673         return 0;
 674
 675 errdesc:
 676         irq_free_descs(virq, 1);
 677 error:
 678         irq_free_virt(virq, 1);
 679         return -1;
 680 }
 681
 682 unsigned int irq_create_direct_mapping(struct irq_host *host)
 683 {
 684         unsigned int virq;
 685
 686         if (host == NULL)
 687                 host = irq_default_host;
 688
 689         BUG_ON(host == NULL);
 690         WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
 691
 692         virq = irq_alloc_virt(host, 1, 0);
 693         if (virq == NO_IRQ) {
 694                 pr_debug("irq: create_direct virq allocation failed\n");
 695                 return NO_IRQ;
 696         }
 697
 698         pr_debug("irq: create_direct obtained virq %d\n", virq);
 699
 700         if (irq_setup_virq(host, virq, virq))
 701                 return NO_IRQ;
 702
 703         return virq;
 704 }
 705
 706 unsigned int irq_create_mapping(struct irq_host *host,
 707                                 irq_hw_number_t hwirq)
 708 {
 709         unsigned int virq, hint;
 710
 711         pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
 712
 713         /* Look for default host if nececssary */
 714         if (host == NULL)
 715                 host = irq_default_host;
 716         if (host == NULL) {
 717                 printk(KERN_WARNING "irq_create_mapping called for"
 718                        " NULL host, hwirq=%lx\n", hwirq);
 719                 WARN_ON(1);
 720                 return NO_IRQ;
 721         }
 722         pr_debug("irq: -> using host @%p\n", host);
 723
 724         /* Check if mapping already exists */
 725         virq = irq_find_mapping(host, hwirq);
 726         if (virq != NO_IRQ) {
 727                 pr_debug("irq: -> existing mapping on virq %d\n", virq);
 728                 return virq;
 729         }
 730
 731         /* Get a virtual interrupt number */
 732         if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
 733                 /* Handle legacy */
 734                 virq = (unsigned int)hwirq;
 735                 if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
 736                         return NO_IRQ;
 737                 return virq;
 738         } else {
 739                 /* Allocate a virtual interrupt number */
 740                 hint = hwirq % irq_virq_count;
 741                 virq = irq_alloc_virt(host, 1, hint);
 742                 if (virq == NO_IRQ) {
 743                         pr_debug("irq: -> virq allocation failed\n");
 744                         return NO_IRQ;
 745                 }
 746         }
 747
 748         if (irq_setup_virq(host, virq, hwirq))
 749                 return NO_IRQ;
 750
 751         pr_debug("irq: irq %lu on host %s mapped to virtual irq %u\n",
 752                 hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 753
 754         return virq;
 755 }
 756 EXPORT_SYMBOL_GPL(irq_create_mapping);
 757
 758 unsigned int irq_create_of_mapping(struct device_node *controller,
 759                                    const u32 *intspec, unsigned int intsize)
 760 {
 761         struct irq_host *host;
 762         irq_hw_number_t hwirq;
 763         unsigned int type = IRQ_TYPE_NONE;
 764         unsigned int virq;
 765
 766         if (controller == NULL)
 767                 host = irq_default_host;
 768         else
 769                 host = irq_find_host(controller);
 770         if (host == NULL) {
 771                 printk(KERN_WARNING "irq: no irq host found for %s !\n",
 772                        controller->full_name);
 773                 return NO_IRQ;
 774         }
 775
 776         /* If host has no translation, then we assume interrupt line */
 777         if (host->ops->xlate == NULL)
 778                 hwirq = intspec[0];
 779         else {
 780                 if (host->ops->xlate(host, controller, intspec, intsize,
 781                                      &hwirq, &type))
 782                         return NO_IRQ;
 783         }
 784
 785         /* Create mapping */
 786         virq = irq_create_mapping(host, hwirq);
 787         if (virq == NO_IRQ)
 788                 return virq;
 789
 790         /* Set type if specified and different than the current one */
 791         if (type != IRQ_TYPE_NONE &&
 792             type != (irqd_get_trigger_type(irq_get_irq_data(virq))))
 793                 irq_set_irq_type(virq, type);
 794         return virq;
 795 }
 796 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 797
 798 void irq_dispose_mapping(unsigned int virq)
 799 {
 800         struct irq_host *host;
 801         irq_hw_number_t hwirq;
 802
 803         if (virq == NO_IRQ)
 804                 return;
 805
 806         host = irq_map[virq].host;
 807         if (WARN_ON(host == NULL))
 808                 return;
 809
 810         /* Never unmap legacy interrupts */
 811         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 812                 return;
 813
 814         irq_set_status_flags(virq, IRQ_NOREQUEST);
 815
 816         /* remove chip and handler */
 817         irq_set_chip_and_handler(virq, NULL, NULL);
 818
 819         /* Make sure it's completed */
 820         synchronize_irq(virq);
 821
 822         /* Tell the PIC about it */
 823         if (host->ops->unmap)
 824                 host->ops->unmap(host, virq);
 825         smp_mb();
 826
 827         /* Clear reverse map */
 828         hwirq = irq_map[virq].hwirq;
 829         switch(host->revmap_type) {
 830         case IRQ_HOST_MAP_LINEAR:
 831                 if (hwirq < host->revmap_data.linear.size)
 832                         host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
 833                 break;
 834         case IRQ_HOST_MAP_TREE:
 835                 mutex_lock(&revmap_trees_mutex);
 836                 radix_tree_delete(&host->revmap_data.tree, hwirq);
 837                 mutex_unlock(&revmap_trees_mutex);
 838                 break;
 839         }
 840
 841         /* Destroy map */
 842         smp_mb();
 843         irq_map[virq].hwirq = host->inval_irq;
 844
 845         irq_free_descs(virq, 1);
 846         /* Free it */
 847         irq_free_virt(virq, 1);
 848 }
 849 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 850
 851 unsigned int irq_find_mapping(struct irq_host *host,
 852                               irq_hw_number_t hwirq)
 853 {
 854         unsigned int i;
 855         unsigned int hint = hwirq % irq_virq_count;
 856
 857         /* Look for default host if nececssary */
 858         if (host == NULL)
 859                 host = irq_default_host;
 860         if (host == NULL)
 861                 return NO_IRQ;
 862
 863         /* legacy -> bail early */
 864         if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
 865                 return hwirq;
 866
 867         /* Slow path does a linear search of the map */
 868         if (hint < NUM_ISA_INTERRUPTS)
 869                 hint = NUM_ISA_INTERRUPTS;
 870         i = hint;
 871         do  {
 872                 if (irq_map[i].host == host &&
 873                     irq_map[i].hwirq == hwirq)
 874                         return i;
 875                 i++;
 876                 if (i >= irq_virq_count)
 877                         i = NUM_ISA_INTERRUPTS;
 878         } while(i != hint);
 879         return NO_IRQ;
 880 }
 881 EXPORT_SYMBOL_GPL(irq_find_mapping);
 882
 883 #ifdef CONFIG_SMP
 884 int irq_choose_cpu(const struct cpumask *mask)
 885 {
 886         int cpuid;
 887
 888         if (cpumask_equal(mask, cpu_all_mask)) {
 889                 static int irq_rover;
 890                 static DEFINE_RAW_SPINLOCK(irq_rover_lock);
 891                 unsigned long flags;
 892
 893                 /* Round-robin distribution... */
 894 do_round_robin:
 895                 raw_spin_lock_irqsave(&irq_rover_lock, flags);
 896
 897                 irq_rover = cpumask_next(irq_rover, cpu_online_mask);
 898                 if (irq_rover >= nr_cpu_ids)
 899                         irq_rover = cpumask_first(cpu_online_mask);
 900
 901                 cpuid = irq_rover;
 902
 903                 raw_spin_unlock_irqrestore(&irq_rover_lock, flags);
 904         } else {
 905                 cpuid = cpumask_first_and(mask, cpu_online_mask);
 906                 if (cpuid >= nr_cpu_ids)
 907                         goto do_round_robin;
 908         }
 909
 910         return get_hard_smp_processor_id(cpuid);
 911 }
 912 #else
 913 int irq_choose_cpu(const struct cpumask *mask)
 914 {
 915         return hard_smp_processor_id();
 916 }
 917 #endif
 918
 919 unsigned int irq_radix_revmap_lookup(struct irq_host *host,
 920                                      irq_hw_number_t hwirq)
 921 {
 922         struct irq_map_entry *ptr;
 923         unsigned int virq;
 924
 925         if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_TREE))
 926                 return irq_find_mapping(host, hwirq);
 927
 928         /*
 929          * The ptr returned references the static global irq_map.
 930          * but freeing an irq can delete nodes along the path to
 931          * do the lookup via call_rcu.
 932          */
 933         rcu_read_lock();
 934         ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
 935         rcu_read_unlock();
 936
 937         /*
 938          * If found in radix tree, then fine.
 939          * Else fallback to linear lookup - this should not happen in practice
 940          * as it means that we failed to insert the node in the radix tree.
 941          */
 942         if (ptr)
 943                 virq = ptr - irq_map;
 944         else
 945                 virq = irq_find_mapping(host, hwirq);
 946
 947         return virq;
 948 }
 949
 950 void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
 951                              irq_hw_number_t hwirq)
 952 {
 953         if (WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE))
 954                 return;
 955
 956         if (virq != NO_IRQ) {
 957                 mutex_lock(&revmap_trees_mutex);
 958                 radix_tree_insert(&host->revmap_data.tree, hwirq,
 959                                   &irq_map[virq]);
 960                 mutex_unlock(&revmap_trees_mutex);
 961         }
 962 }
 963
 964 unsigned int irq_linear_revmap(struct irq_host *host,
 965                                irq_hw_number_t hwirq)
 966 {
 967         unsigned int *revmap;
 968
 969         if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_LINEAR))
 970                 return irq_find_mapping(host, hwirq);
 971
 972         /* Check revmap bounds */
 973         if (unlikely(hwirq >= host->revmap_data.linear.size))
 974                 return irq_find_mapping(host, hwirq);
 975
 976         /* Check if revmap was allocated */
 977         revmap = host->revmap_data.linear.revmap;
 978         if (unlikely(revmap == NULL))
 979                 return irq_find_mapping(host, hwirq);
 980
 981         /* Fill up revmap with slow path if no mapping found */
 982         if (unlikely(revmap[hwirq] == NO_IRQ))
 983                 revmap[hwirq] = irq_find_mapping(host, hwirq);
 984
 985         return revmap[hwirq];
 986 }
 987
 988 unsigned int irq_alloc_virt(struct irq_host *host,
 989                             unsigned int count,
 990                             unsigned int hint)
 991 {
 992         unsigned long flags;
 993         unsigned int i, j, found = NO_IRQ;
 994
 995         if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
 996                 return NO_IRQ;
 997
 998         raw_spin_lock_irqsave(&irq_big_lock, flags);
 999
1000         /* Use hint for 1 interrupt if any */
1001         if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
1002             hint < irq_virq_count && irq_map[hint].host == NULL) {
1003                 found = hint;
1004                 goto hint_found;
1005         }
1006
1007         /* Look for count consecutive numbers in the allocatable
1008          * (non-legacy) space
1009          */
1010         for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
1011                 if (irq_map[i].host != NULL)
1012                         j = 0;
1013                 else
1014                         j++;
1015
1016                 if (j == count) {
1017                         found = i - count + 1;
1018                         break;
1019                 }
1020         }
1021         if (found == NO_IRQ) {
1022                 raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1023                 return NO_IRQ;
1024         }
1025  hint_found:
1026         for (i = found; i < (found + count); i++) {
1027                 irq_map[i].hwirq = host->inval_irq;
1028                 smp_wmb();
1029                 irq_map[i].host = host;
1030         }
1031         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1032         return found;
1033 }
1034
1035 void irq_free_virt(unsigned int virq, unsigned int count)
1036 {
1037         unsigned long flags;
1038         unsigned int i;
1039
1040         WARN_ON (virq < NUM_ISA_INTERRUPTS);
1041         WARN_ON (count == 0 || (virq + count) > irq_virq_count);
1042
1043         if (virq < NUM_ISA_INTERRUPTS) {
1044                 if (virq + count < NUM_ISA_INTERRUPTS)
1045                         return;
1046                 count  =- NUM_ISA_INTERRUPTS - virq;
1047                 virq = NUM_ISA_INTERRUPTS;
1048         }
1049
1050         if (count > irq_virq_count || virq > irq_virq_count - count) {
1051                 if (virq > irq_virq_count)
1052                         return;
1053                 count = irq_virq_count - virq;
1054         }
1055
1056         raw_spin_lock_irqsave(&irq_big_lock, flags);
1057         for (i = virq; i < (virq + count); i++) {
1058                 struct irq_host *host;
1059
1060                 host = irq_map[i].host;
1061                 irq_map[i].hwirq = host->inval_irq;
1062                 smp_wmb();
1063                 irq_map[i].host = NULL;
1064         }
1065         raw_spin_unlock_irqrestore(&irq_big_lock, flags);
1066 }
1067
1068 int arch_early_irq_init(void)
1069 {
1070         return 0;
1071 }
1072
1073 #ifdef CONFIG_VIRQ_DEBUG
1074 static int virq_debug_show(struct seq_file *m, void *private)
1075 {
1076         unsigned long flags;
1077         struct irq_desc *desc;
1078         const char *p;
1079         static const char none[] = "none";
1080         void *data;
1081         int i;
1082
1083         seq_printf(m, "%-5s  %-7s  %-15s  %-18s  %s\n", "virq", "hwirq",
1084                       "chip name", "chip data", "host name");
1085
1086         for (i = 1; i < nr_irqs; i++) {
1087                 desc = irq_to_desc(i);
1088                 if (!desc)
1089                         continue;
1090
1091                 raw_spin_lock_irqsave(&desc->lock, flags);
1092
1093                 if (desc->action && desc->action->handler) {
1094                         struct irq_chip *chip;
1095
1096                         seq_printf(m, "%5d  ", i);
1097                         seq_printf(m, "0x%05lx  ", irq_map[i].hwirq);
1098
1099                         chip = irq_desc_get_chip(desc);
1100                         if (chip && chip->name)
1101                                 p = chip->name;
1102                         else
1103                                 p = none;
1104                         seq_printf(m, "%-15s  ", p);
1105
1106                         data = irq_desc_get_chip_data(desc);
1107                         seq_printf(m, "0x%16p  ", data);
1108
1109                         if (irq_map[i].host && irq_map[i].host->of_node)
1110                                 p = irq_map[i].host->of_node->full_name;
1111                         else
1112                                 p = none;
1113                         seq_printf(m, "%s\n", p);
1114                 }
1115
1116                 raw_spin_unlock_irqrestore(&desc->lock, flags);
1117         }
1118
1119         return 0;
1120 }
1121
1122 static int virq_debug_open(struct inode *inode, struct file *file)
1123 {
1124         return single_open(file, virq_debug_show, inode->i_private);
1125 }
1126
1127 static const struct file_operations virq_debug_fops = {
1128         .open = virq_debug_open,
1129         .read = seq_read,
1130         .llseek = seq_lseek,
1131         .release = single_release,
1132 };
1133
1134 static int __init irq_debugfs_init(void)
1135 {
1136         if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
1137                                  NULL, &virq_debug_fops) == NULL)
1138                 return -ENOMEM;
1139
1140         return 0;
1141 }
1142 __initcall(irq_debugfs_init);
1143 #endif /* CONFIG_VIRQ_DEBUG */
1144
1145 #ifdef CONFIG_PPC64
1146 static int __init setup_noirqdistrib(char *str)
1147 {
1148         distribute_irqs = 0;
1149         return 1;
1150 }
1151
1152 __setup("noirqdistrib", setup_noirqdistrib);
1153 #endif /* CONFIG_PPC64 */